Pump



Patented ug. 4, A1936 UNITED STATES PUMP Kurt Schoene, Hamburg, Germany Application December s, 41934, serial Ne. 755,826 In Germany December 27, 1933 l Claim.

This invention relates to plunger pumps, and particularly relates to means for .guiding the plungers of vertical plunger pumps.

In a vertical plunger pump, it is desirable to keep the overall height of the pump to the absolute minimum, in order to reduce the suction head. Where an ordinary trunk piston is used and mounted directly above the crank case, a number of difllculties are encountered. vWater leaking past the piston will pass to the crank case and become mixed with the oil which is highly objectionable, particularly where forced lubrication is adopted.

In v'such pumps it -is customary to use a long trunk piston and lubricate only the lower end ofthe-piston, reliance being placed on the water to lubricate the upper end. Where clean water is being pumped this arrangement is objectionable because it is inevitable that a portion of watercontaining grit or sand is pumped, a certain amount of grit is carried between the working surfaces of the pistonand the cylinder so that severe wear occurs, particularly in View of the side thrust exerted by the pitman or connecting rod. The primary purpose of the present inventionlis to avoid this diiliculty.

The piston is of the trunk type, having ahead and skirt and works in a cylinder. The piston,

however,l is not guided primarily by the cylinder,

but is rigidly connected to a cross-head which works in ways, whose upper end terminates Within the skirt of the piston in all piston positions.

The cross-head is lubricated with oil, but between the piston and the cylinder wall, reliance is placed on water lubrication. `Because the upper vend of the cross-head guides are within and above the lower margin of the piston skirt, there is no possibility for the oil and water to become mixed. On the contrary, any water leaking between the piston and the cylinder drains away without entering the crosshead guides, Consel quently no water can enter the crank case and no 4,5j oil can ever contaminate the water being pumped.

Furthermore, the cross-head and guides take up the lateral thrust of the pitman so that even if some grit does penetrate between the piston and cylinder, the abrasive action will be kept to a minimum because the lateral thrust developed by eo the oil will come in contact with the water and contaminate the same. On the other hand, where y pin at 1.

crank pin is indicated by the dot and dash line (Cl. 10S-205) ciprocating sleeve valve, the inlet ports being so arranged as to deliver a portion of the kinetic energy of the entering water to the pump plunger. This type of pump is described and claimed in my U. S. Patent No. 1,760,171, issued May 27, 5

As thus embodied, the invention is illustrated in the accompanying drawing, in which the single gure is a vertical axial section through a pump cylinder and piston with guiding means 10 constructed according to my invention.

In this` drawing only those elements which enter directly into the claimed combination are illustrated. Thus only the upper portion of the crank case is shown, it being understood that 15 according to common practice the crank case will enclose the crank shaft and crank. 'Ihe upper end of the pump chamber and the discharge valves are omitted altogether, and only a portion of the main frame or housing is shown. 20

The crank shaft is indicated at 6 and the crank The orbit of the center line of the A. The connecting rod or pitman is indicated at 8. 9 represents the upper portion of the crank 25 case which is formed with an upstanding cylindrical cross-head guide member II. The cylinder is indicated at I2 and is supported in a yoke 'I3 which is suspended by the webs I4 which are or may be formed integral with the upper por- 30 Working in the cylinder I 2 is a piston made up'35 of a. head I1 with central hub I8 and a peripheral depending skirt I9; No packing rings-or other packing means are shown, but if packing means are used they may conform to known practice without aiecting the present invention. Slid- 40 able in the guide I I is a cross-head which is structurally similar to a conventional trunk'-l piston, that is to say, it has a head 2| and a pendant skirt 22, the skirt tting within the guide l I. At the center of the head 2l is a hub 23 which abuts 45 the hub I8. A bolt 24 with nut 25 serves to hold the hubs I8 and 23 is assembled relation so that the cross-head and the piston reciprocate as a unit. The nut 25 is specially formed as shown to conform to the desired contour of the piston head. 50 In this respect it will be observed that features characteristic of my prior patent are included.

The parts are so arranged that as the piston vre'ciprocates the lower margin of the skirt I9 is always below the upper end of the cross-head guide Il so that a portion of the skirt always encirclesa portion of the cross-head guide and is spaced therefrom a. substantial distance, as indicated in the drawing. The connecting rod or pitman 8v is connected with the skirt portion 22 of the cross-head by means of a wrist pin, conventionally represented at 26, so located that as the cross head reciprocates the limits of travel of the wrist pin are well within the longitudinal limits of guide Il.

It will be observed that as the crank is rotated the piston and cross-head will be reciprocated. 'I'he cross-head and its guide absorb the lateral thrust of the pitman 8 so that the pitman exerts no lateral thrust upon the piston.

While leakage between the cylinder wall and the piston is not contemplated, if leakage occurs between the cylinder wall and the skirt I9 it will drain away, 'cylinder wall l2 being spaced from the upper wall 9 of the crank case to permit this drainage flow.

Since the cross-head guide Il is an upstandguiding t for the cross-head may be used. This insures the elimination of-side thrust on the piston and minimizes the abrasive eiect of su ch grit as may enter between the piston skirt and cylinder wall.

It will be observed that as a result of the con-J struction above described, the height of the piston head above the wrist pin is little if at all increased as compared to a similar structure of conventional type using a long trunk piston or plunger. -From this it follows that the overall height of the pump is not increased.

The actuating means-for the sleeve valve I6 is not shown, not being a part of the present invention. 'I'he use of conventional means, such as eccentrics4 and eccentric rods, is contemplated.

While the invention is particularly intended for use in conjunction with the type of pump disclosed in my patent above identified, itis susceptible of use with pumps of other types, specifically, with l pumps having conventional inlet -and discharge l5 mechanisms.

What is claimed is,-

In a plunger pump for liquids, the combination of a substantially vertical cylinder; a member forming the upper portion of a crank case, rig.- 20 idly connected with but spaced from said cylinder, and having a tubular cross head guide longer than the working stroke of the plunger extending upward to a point within the cylinder; a

piston working in the cylinder and having a head,

cross head that the limits of travel of the wrist pin are within the longitudinal limits of the guide, and the piston head at its lower limit of motion closely approaches the upper end ofthe guide.

' KURT SCHOENE. 

